(19)
(11) EP 0 228 136 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
21.03.1990 Bulletin 1990/12

(43) Date of publication A2:
08.07.1987 Bulletin 1987/28

(21) Application number: 86202317.3

(22) Date of filing: 18.12.1986
(51) International Patent Classification (IPC)4G09G 1/16
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 30.12.1985 US 815362

(71) Applicant: Philips Electronics N.V.
5621 BA Eindhoven (NL)

(72) Inventors:
  • Kaplinsky, Cecil Hertz
    NL-5656 AA Eindhoven (NL)
  • Li, Jan-Kwei Jack
    NL-5656 AA Eindhoven (NL)

(74) Representative: Strijland, Wilfred et al
INTERNATIONAAL OCTROOIBUREAU B.V., Prof. Holstlaan 6
5656 AA Eindhoven
5656 AA Eindhoven (NL)


(56) References cited: : 
   
       


    (54) Abstract operation-signalling from a raster scan video controller to a display memory


    (57) A generalized operation-signalling logic for a raster scan video controller whereby the video controller, in accessing the memory of a computer system, can indicate what type of operation is to be performed at each memory address to be accessed. The signalling scheme provides a rich set of functions, logic to generate this signalling and an external PLA-type device which interprets this signalling for a wide variety of memory types.





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